Your box of many buttons does coax only...
It's very possible that the front TV is set to use HDMI, or RGB + LR RCA cables from the dish box.
Ours, the TV antenna, park cable jack, and an output off of the dish receiver are inputs to the box of many buttons, and send signals to all 3 TV's when TV is selected.
But the front TV is also wired with RCA's, R G B + L R, which go to the DVD player, and another set to the satellite box.
So the bedroom tv is always looking at it's coax input on channel 3.
But the front TV is not, it see's the "Bomb" when input is set to TV, the DVD when input is set to "input 2", and the satellite when input is set to "input 3"
newer moho's, with hdmi and such, may differ greatly.